NAIROBI — If elections were held today in the Democratic Republic of the Congo, exiled former Gov. Moise Katumbi would trounce incumbent President Joseph Kabila by a more than 4-1 margin, a new political opinion poll finds.

The rare public opinion survey in Africa’s second-largest country suggests that massive popular unrest could be on the horizon. Not only is the president increasingly unpopular, but 48 percent of respondents said they would take to the streets if the vote is either delayed or rigged — a foregone conclusion at this point since a portion of the opposition has agreed to postpone the general election until 2018.

Just 7.8 percent of respondents said they would vote for Kabila, compared with 33 percent who said they would vote for Katumbi. Another 18 percent said they would support veteran opposition leader Etienne Tshisekedi and 7 percent said they would back Vital Kamerhe, leader of the Union for the Congolese Nation party.

A resounding 81.4 percent of respondents opposed amending the constitution to allow Kabila to seek a third term, as leaders in neighboring Rwanda and Republic of Congo have done, and 74.3 percent said the president should leave office when his term ends on Dec. 19.

The nationally representative poll of 7,545 Congolese was conducted by the Kinshasa-based Bureau d’Études, de Recherches, et Consulting International, and the Congo Research Group at New York University. It comes in the midst of a deepening political crisis of the president’s making. The ruling coalition has said that elections cannot be held as planned this year because of the logistical difficulty of updating voter rolls, a claim the opposition mostly rejects as an excuse for Kabila to cling to power.

Last week, Kabila struck a deal with some members of the opposition that would allow him to remain in office until April 2018. The main opposition coalition refused to participate in the negotiations, however, and rejected the accord as a “flagrant violation” of the constitution. It staged a nationwide strike to warn Kabila — or, in the football parlance preferred by Congolese politicians, to give him a “yellow card” — and said the president will get a “red card” if he remains in office after Dec. 19.

“It is certainly troubling that over half of the Congolese population would vote for candidates who are excluded by this recent deal,” Jason Stearns, who leads the Congo Research Group at NYU, told Foreign Policy in an email. “However it is also clear that the Congolese want a negotiated solution to the current impasse, so this pool both lends credibility to [the opposition], but also highlights the need for a peaceful solution.”

In September, at least 53 people were killed when protests against electoral delays turned violent.

Kabila came to power after the 2001 assassination of his father, rebel leader-turned President Laurent Kabila, and won disputed elections in 2006 and 2011. The new poll reveals a dramatic collapse in support for the president, who received more than 48 percent of the vote five years ago, according to official tallies.

Katumbi, a charismatic former governor of the mineral-rich Katanga province, declared his candidacy for president in May. Soon after, Kabila’s government accused him of recruiting American mercenaries as part of an alleged coup plot. He was later sentenced in absentia to three years in prison on the lesser charge of illegally selling property, a conviction that government critics dismissed as a blatant attempt to prevent the popular former governor from pushing ahead with his campaign.

Last month, the U.N. envoy to Congo, Maman Sambo Sidikou, warned that the country had “entered a period of extreme risk to its stability” because of the political impasse surrounding elections.

“If this trajectory continues, I believe large-scale violence is all but inevitable,” he said.